The alert cited cases reported outside of China, including patients in South Korea, home to 28,500 U.S. troops, and Japan.
Risa Takenouchi, 26, entered the academy in the western region of Hiroshima along with about 20 men.
Shinzo Abe pledged to bolster his country's role under its pact with the U.S. in “outer space and cyberspace.”
The Yokosuka-based guided-missile cruiser USS Shiloh sailed through the strait on Thursday.
Tokyo officials detected the chemicals, commonly known as PFOS and PFOA, in two wells near Yokota Air Base.
The wrecked boat was found on Sado Island by the Japanese Coast Guard.
Washington had urged Tokyo to join a U.S.-led coalition patrol force in the Strait of Hormuz.
Americans assigned to Air Force bases in Europe could soon be paying higher rents for off-base homes.
Two false alarms sounded Thursday night and Friday morning hundreds of miles and hours apart in South Korea and Japan.
U.S. Marine Corps Air Station Futenma is to be moved from Ginowan to the previously undeveloped Henoko area.